Production and Business Performance Enhancement of the Elver Eel (Anguilla bicolor bicolor) Nursery with Different Stocking Densities in a Recirculating Aquaculture System

This study aimed to evaluate the effect of nursery for elver eels (Anguilla bicolor bicolor) with different stocking densities in a recirculation aquaculture system on production and business performance. The nursery was conducted in the eel cultivation business unit located in Bogor Regency, West Java, Indonesia. The nursery used the non-equivalent control group design method. Treatments consisted of nurseries with different stocking densities, consisting of one control group (4kg/ m³) and two treatment groups (5 and 6kg/ m³). Each group was repeated four times. The eel (A. bicolor bicolor) tested weighed 9,65±0,80g/ eel. The nursery was carried out for 60 days of maintenance, moreover it used 12 units of a circular fiberglass tank (0,5m³ of water) with a recirculation system. Commercial feed (50% protein) in the form of a paste was given twice a day at a feeding rate of 2,0–2,8%/day. The final average weight of eels in the 5kg/ m³ treatment (19,71±0,13 g) was greater than in the 4kg/ m³ (18,75±1,04g) and 6kg/ m³ (16,37±1,66g). The best productivity (10,14±0,08g/ L), absolute growth rate (0,17±0,00g/ day), specific growth rate (1,19±0,01%/ day), and biomass absolute growth rate (42,83±0,67g/ day) were obtained in the 5kg/ m³ treatment. The coefficient of weight variation of the 4 and 5kg/ m³ treatments was significantly different from the 6kg/ m³ treatment. Survival rates and feed conversion ratios did not differ significantly between treatments. The best business performance was obtained in the 5kg/ m³ treatment (payback period = 5,25 years and R/C ratio = 1,25). The best production and business performance enhancement of elver eel (A. bicolor bicolor) nurseries with different stocking densities in a recirculating aquaculture system were obtained in the 5kg /m³ treatment.